


Lux Aeterna | The Breakthrough

by Luciferious



Category: Supernatural
Genre: Alternate Universe - Canon Divergence, Boy King Sam, M/M
Language: English
Status: Completed
Published: 2012-10-05
Updated: 2012-10-05
Packaged: 2017-11-25 23:13:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,504
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/643985
Author URL: https://archiveofourown.org/users/Luciferious/pseuds/Luciferious
Summary: <blockquote class="userstuff">
              <p>Castiel trains Sam to harness his powers. Sam reaches his limits, but Castiel isn't willing to compromise.</p><p>Part of a much larger story.</p>
            </blockquote>





	Lux Aeterna | The Breakthrough

“I can’t. I can’t do it.”  
  
Sam’s voice rings out harsh and panicked, echoing off walls unseen in the darkness beyond their one small pool of yellowed light. Doves coo and flap their wings in the cross beams above, startled, but the sound dies quickly and leaves nothing in its wake save the far-off wail of a car alarm. They’ve been at this for hours now; back and forth since sundown, and dawn is coming soon enough. Sam is so _tired_ , Castiel can feel his exhaustion pulsating through the humid summer air. But they’re not finished yet. They’ve come too far to stop right now, and they will be here in this rotten warehouse until it is done. No matter how long it takes.  
  
“Yes, you can.” Castiel heaves a sigh and pushes off an empty shipping crate with a weighted _creak_ , circling just along the perimeter, just in the edge of the shadows. He eyes Sam carefully, takes in his slumped shoulders, the sweat-matted hair framing his face. Sam’s chest heaves from the force of his breaths and he wipes blood trickling from his nose with the back of a shaken hand, and there is no doubt that Castiel feels for the boy. He knows this is difficult, knows he is asking too much, but that is the point; Sam needs to be pushed.  
  
“I’ve shown you the way, Sam. You have everything you need at your disposal. All you have to do is concentrate.”  
  
Sam scoffs and something in Castiel’s chest sours at the sound. He frowns, ever-so-slightly, but says nothing, watching as Sam pushes himself up from his perch balanced between his feet, pacing in and out of the lamplight.  
  
“I know. I know, it’s... it’s _right there_ , I can feel it. But I can’t....” Sam trails off, runs a hand through his hair, and Castiel crosses his arms over his chest, waiting to see what Sam will do. This is already his fifth attempt, and Castiel can’t help his growing impatience, despite his best intentions. He has waited a millennia—a few more hours should seem a drop in the ocean of all that passivity, but with the end so close now, Castiel finds _minutes_ excruciating in the same way centuries once were.  
  
“It’s like trying to catch _smoke_.” Sam’s hands are on his hips now, staring down at the floor between them. His gaze is enough to burrow holes in the concrete, determined in every way Cas needs him to be, but it’s for naught buried beneath his desperation. Beneath his uncertainty and his _doubt_.  
  
Tonight, Castiel means to drive that out of him.  
  
“Sam—” But Sam cuts him off, clears his throat and rolls a shoulder. Castiel sighs once more unbidden, but either Sam doesn’t notice or chooses to ignore it, focusing instead on the table set centered beneath the light.  
  
Sam’s hands are filthy, covered in dirt and dust and blood. They’ve been squatting here for two weeks already, and it shows on their skin and in the stale smell of old sweat lingering around them. Castiel himself can’t help but bitterly wish for a shower, a real bed—with his grace waning by the day, he is more and more distracted by the filth clinging to him, the way his skin feels against stiff clothes. He shifts uncomfortably between his feet and watches as Sam raises one blood-smeared hand, watches him trembling slightly, steadied only by a locked elbow and and wider stance. Castiel waits, feels the air prickle and shift, feels the hair on his arms stand as Sam’s eyes go closed, and the light above them begins to swing.  
  
Castiel stand straighter, breath held, but just as quickly as it began, Sam is sinking down to a knee again, folding in on himself with a whimper.  
  
“I _can’t_. Cas, I can’t, I need more. I’m not....”  
  
“Not what? Strong enough?” Cas’ tone is harsher than he intends, but patience is a virtue he’s sure he no longer possesses, hands dropping exasperated at his side. He rounds the corner of the table, casting a dark shadow over Sam’s face before he kneels next to him. Cas can _smell_ the frustration on him, and it mirrors his own, eyes narrowed as he catches Sam’s gaze and holds firm. “You don’t _need_ more. We’ve discussed this. The blood is a facilitator—it affects the body, not the mind. Your power is your own, and you must learn to wield it unassisted. This is _paramount_ , Sam.”  
  
“And what if I don’t?” Sam’s eyes are sharp, teeth bared as his words clap off the walls harsher than they left his lips. The birds in the rafters above shuffle, agitated, and Cas is taken aback by Sam’s audacity. He frowns hard, torn between concern and a measure of anger as Sam stands, wanders off into the dark shaking and clearly pushed so far past his limits, Cas begins to worry he was wrong.  
  
“What if I don’t learn? It’s too much, Cas. Too _big_. I feel like... like my head’s gonna _explode_. My eyes go dark and I can’t fucking _breathe_.”  
  
“You _will_ learn.” Castiel rises to his feet, but doesn’t follow, rough fingertips grazing the edge of the table. “You were made for this. You have to let go of your doubt and understand that. _Believe_ it.”  
  
Castiel runs a weary hand over his face. He has been leading Sam along this path for the better part of a year now, and Sam has excelled at every turn, taken to everything from magick to telekinesis—he doesn’t understand how Sam can still doubt after all he has accomplished, how this one task could prove to be the insurmountable obstacle in their path. They are running out of resources, out of friends, out of safe places to hide. Most importantly, they are running out of time, and a setback now could jeopardize _everything_.  
  
That is a risk Castiel is not willing to take.  
  
“You’re afraid,” he continues, watching as Sam approaches, braces his shaking hands against the lip of the table. “You can’t be. If there is one thing you _cannot_ be, it’s afraid of your own potential. You’re fighting yourself when you should be _embracing_ this—”  
  
Sam beats his fist against the wood hard enough that it shakes through the floor, hangs his head low between his arms, hair hiding his face. Castiel grinds his jaw, but says nothing more—he will do anything he must to push Sam in the right direction, but not at the risk of undoing him.  
  
Slowly, Sam stretches up to full height, wiping the sweat from his forehead with his sleeve.  
  
“ _Focus_ , Sam.” Castiel coaches, feeling the air grow thick and electric as Sam lifts his hand once more. Sam concentrates, focuses his energy, teeth bared and chest heaving, and Cas is so sure he’ll do it this time, so certain that he almost smiles as the light flickers and the windows rattle. The birds roosting above take off for good, wingbeats barely audible over the pounding of Castiel’s own heart in his ears, but it’s not a moment later that Sam lets out a cry of frustration, swings his arm around to the back of his head and walks away.  
  
“No, I can’t do this, Cas. I’m not ready. I’m not—”  
  
Castiel has had _enough_.  
  
Sam is barely steady on his feet again before Castiel has a hand around his throat, squeezing tight enough that Sam sputters and wheezes in his grip. Castiel’s eyes are lit-up with all the rage and frustration he’s been burying all night, all the desperation he’s been so careful to hide, and when Sam grabs for his wrist, claws at his hand, Castiel presses him neatly back against a rotted crate, head cocked and teeth bared.  
  
“You _will_ do this. Do you understand?” Sam coughs and pulls at Cas’ wrist, eyes wide and just shy of panicked. Something in Cas fears he has gone too far this time—Sam’s own self-doubt may make him stubborn beyond Castiel’s comprehension, but Sam is precious, and Castiel would never dare do him harm. But it’s too late now. Castiel pulls him in close, nose to nose and eye to eye, so he can feel Sam’s gasped breaths beat hot against his face.  
  
“ _You will not fail me_.” Castiel holds Sam there, holds his gaze and waits for the words to sink in, waits for Sam to truly begin to understand the seriousness of this situation. It’s _dire_ , more than Sam will ever know. More than Castiel is certain he wants Sam to know.  
  
“More importantly, you will not fail _him_.”  
  
And that’s it. That’s what does it. All in a moment, Sam stops struggling, hisses in as deep a breath as he can manage and nods in Castiel’s grip. Because this isn’t about them— _none of this is_ about them. Or power, or honor. Or _pride_.  
  
It’s about _justice_. Making right an eternity’s worth of wrongs. About carrying out the task that has been entrusted to them, that no one else left on this earth, in Heaven or in Hell can manage.  
  
This is about Lucifer. About raising the Morningstar from his prison.  
  
This is about _loyalty_.  
  
“Okay....” There’s a determination in Sam’s face again, stronger now than it has been all night, and Cas finally eases his hold on Sam until he slips from his grip, the soles of his boots settling back flat on the concrete floor. Sam clears his throat, rubs his neck, and his expression goes tense along the weight of the world settling on his shoulders. Cas won’t admit it, but he hates to see the toll Sam’s burden has taken on him, the way it dims his eyes and slopes his shoulders. But, like many other a terrible thing in this world, it is _necessary_. Sam must understand what is at stake.  
  
“Okay.” Sam shuffles around Castiel, back toward the table. His hands are shaking still, but there’s a sureness in his motions that gives Castiel hope. Watchful as always, Castiel’s eyes are trained on Sam’s hand as he lifts it, as he steadies his stance. And something in the air is different this time—Castiel feels it right away, feels it in the warm prickle that rushes up his arms, in the electricity in the air as the light dims.  
  
Sam stands strong. His breathing is steady now, eyes shut, but not tight—none of that desperate, agonizing _clawing_ for strength of before in him now. Castiel holds borrowed breath and stands tall as Sam opens his eyes. He sees the ruddy glow of gold in them with ease even in this dim light, and his heart begins to pound as he moves in toward the table, into Sam’s line of sight.  
  
“Touch it,” he says quietly, gesturing to the small form lying still and bloody in the center of the table. “Put your hand on it.”  
  
And Sam does, reaches out slowly and cups his hand around bent and matted feathers. There’s a shudder almost immediately, a sudden shock of movement. The light above them swings violently and suddenly bursts, but even through the shower of sparks that follow, sending Castiel back a step with an arm shielding his face, he hears it—chirping. The rustling of wings.  
  
He’s done it.  
  
Sam is breathing hard again, shoulders slumping as his eyes dim and fade into familiar hazel. All is still, the both of them silent, on-edge. But slowly, Sam turns his hand over. Slowly, he opens his palm. And all this frustration and anger is suddenly worth it.  
  
The sparrow stands, and flies away.  
  
“I did it.” Sam’s voice is breathy, chased with a laugh that’s as much shock as it is giddy relief. His gaze follows the sparrow’s path through the warehouse until it disappears into the darkness, and then he’s looking at Cas, that endearing lopsided smile spread wide across his face. “I did it, I actually....”  
  
Castiel nods, finding himself suddenly at a loss for words. Though there was never a doubt in his mind that Sam was capable, that doesn’t lessen the very obvious truth that he has just witnessed a miracle. And it would be a lie to claim he didn’t feel a little in awe of Sam in this moment.  
  
Sam’s grin only spreads, and despite how exhausted he looks, there’s more life in him now than Castiel has seen in weeks.  
  
He rounds the corner of the table, arms out, and before Castiel knows it, Sam is wrapping him up in a tight hug, face buried tight in the crook of Cas’ neck. This isn’t like the other times. Honing telekinetic abilities left Sam drained, even irritated and ready for sleep. After exorcisms, Sam more often than not needed time to himself—a long walk, an even longer drive, despite Castiel’s protesting of Sam going anywhere alone. But this is different; Sam is all but buzzing with adrenaline, and it’s a feeling that’s infectious, Castiel’s arms coming to encircle Sam’s back, cradling him close.  
  
“ _Thank you_ ,” Sam breathes, and it’s so sincere that Castiel hardly knows what to do with it, only holding tighter until Sam pulls back just-so, just enough to catch his eyes and smile. Castiel has no choice but to smile back.  
  
He does understand, when all is said and done. He truly does. Despite all that Castiel has taught Sam in the last year, all that he has come to understand about his part to play, Castiel knows there is still a part of Sam that feels cursed. The part of him that cannot reconcile his mother’s death, and Jess and _Dean_ with the blood that flows through his veins. Castiel would never ask him to. Sam’s life has been one tragedy after another, and he would never dare insult Sam, belittle his pain with assurances of a _greater good_. Sam sees the loss his purpose has forced him to bear, sees the death and pain and violence this power of his can and _has_ wrought, and with a clearer mind and sounder heart, Castiel does not blame him for fighting. He does not blame him for railing against this part of himself he can’t help but see as _tainted_.  
  
But this is different. For the first time, Sam sees his potential for what it is, not what he fears it could be. He sees the true reach of his ability, sees that he has not just been given power over death, but _life_.  
  
Sam understands now what Castiel has understood all along: what Sam is, what he is capable of is a _gift_. And one far too precious to be squandered.  
  
“You are ready, Sam,” Castiel murmurs, curling a hand gently around the crook of Sam’s neck. There is something overwhelmed and so, so incredibly gracious in Sam’s expression, Castiel finds himself a little in awe all over again.  
  
Before he can say more, Sam stops him with a kiss.


End file.
